SPRING CENTRALISER WITH AUTOMATIC LOCKING AT CASING STRING Russian patent published in 2013 - IPC E21B17/00 

FIELD: oil-and-gas industry.

SUBSTANCE: spring centraliser to be automatically locked at casing column consists of centering plates and two seamless rings. Ends of said seamless rings are jointed by weld seam. Note here that lower ring has special inclined two-six pockets (depending upon centraliser size). Said inclined pockets accommodate two forged rolls coupled by torsion spring locked by retainer in transport position. Centraliser locking in rolls displacement by the spring in wedge pocket after removal of retainer is effected by the principle of overrunning coupling. Wedge pocket is formed by centraliser ring and casing column. One roll lock centraliser against downward displacement while another one inhibits upward displacement.

EFFECT: perfected design.

2 dwg